Preliminary studies on the use of modified ALCELL lignin as a coupling agent in the biofiber composites

ALCELL lignin has been employed as a coupling agent in empty fruit bunch fi ber (EFBF)-polypropylene (PP) composites. The lignin has been chemically mo dified with toluene diisolcyanate (TDI) to various weight loadings. The evi dence of the reaction between TDI and lignin has been observed by using Fou rier transform infrared (FTIR) analysis. The effect of lignin as a coupling agent on mechanical properties has been studied. The results show that the TDI-modified lignin is able to impart greater compatibility between EFBF a nd PP. This is reflected in the greater mechanical properties shown by the composites with TDI-modified lignin than in those with the unmodified ligni n. Scanning electron microscopy (SEM) studies showed that TDI modification of lignin resulted in a better blending and compatibility between lignin an d PP matrix. The glass-transition temperature of the lignin increases as th e WPG is increased. (C) 2001 John Wiley & Sons, Inc.